Digital cameras have recently come into widespread use. Digital cameras produce images of a scene which may be stored on a memory card, or the like as digital data. Such digital data can easily be processed by a computer and can easily be distributed through the Internet or other network to friends and family.
In a digital still camera, the quality of a picture generally varies greatly depending on exposure conditions. To control exposure, a camera has an automatic-exposure or AE mechanism for setting an appropriate exposure in response to how bright the light is when a picture is recorded and to a luminance distribution on a target object. However, even an AE mechanism has a limit, and it is not necessarily guaranteed that an optimal picture can always be recorded. Occasionally, the digital camera will process an image using incorrect illuminant parameters, for example, with parameters appropriate for fluorescent lighting when the lighting was actually incandescent. Processing an image according to an incorrect illuminant can, of course, substantially distort the processed picture. Also, in many cases, when a picture is taken with a digital camera, the user may prefer a lighter or darker image, or one with a different color balance, even though the original picture is adequate.
For these reasons, many digital cameras require extensive post-processing of images. Correctable flaws in pictures, including tone, color balance, and image sharpening can be minimized, and user preferences can be incorporated in post-processing. However, post-processing can be expensive for the photographer, both in the cost of appropriate software and an appropriate computer. It can also be tedious and time consuming to correct and perfect each image. Thus, a photographer may abandon the digital camera in favor of the more traditional film camera, which creates images that can be developed and printed immediately.